1. Field of the Invention
The present invention relates to air bubble detectors. More specifically, the present invention relates to a universal air bubble detector which is usable with a variety of different tubing sizes and usable in a variety of different applications.
2. State of the Art
Air bubble detectors are used in many situations where it is desirable to detect the presence of an air bubble, particularly in a tube carrying a liquid. In many applications, such as the medical and health care industries, tubing is used to deliver various fluids to a person, and it is often important to detect air bubbles before they are accidentally delivered to the patient. In industry, they can be used to ensure that liquids do not have excessive amounts of air to ensure proper volume flows or reactions.
Some equipment, such as peristaltic pumps, is now available with air bubble detectors. These detectors, however, monitor air bubbles at the pump and cannot check for air bubbles downstream from the pump, as may be introduced through fittings, connectors, or other equipment. It is often desirable to monitor for air bubbles downstream from the equipment and as close to the patient as possible to monitor for the introduction of air from all possible sources. There is thus a need for an air bubble detector which is capable of monitoring for air bubbles very near the point of injection of the solution into the patient, such as by attaching to a delivery tubing near the patient, or at any desired location.
Additionally, many devices are not yet available with air bubble detectors. It is often prohibitively expensive to replace equipment, or to redesign equipment to include an air bubble detector. Thus, the cost of replacing equipment or designing and manufacturing an air bubble detector may prevent the use of the same in situations where it is otherwise desirable to have the detector. There is, therefore, a need for an air bubble detector which may be attached to or used in combination with existing devices without requiring replacement or extensive modification of the device.
There are also many situations where a small number of air bubble detectors are desired, whether for a device which is produced in a limited quantity or for a project or procedure which is infrequently performed, etc. In such a situation, current air bubble detector technologies impede the use of an air bubble detector, as the detectors are typically custom manufactured for a particular application. It is appreciated that it is typically too expensive to design, create molds and tooling, and manufacture an air bubble detector where only limited quantity is desired. There is thus a need for an air bubble detector which may be used in a variety of situations, accommodating a variety of different sizes of tubing, etc.
Many available air bubble detectors function by passing a signal through the tubing and fluid and receiving the signal. The received signal is evaluated to determine if an air bubble is present. These detectors are designed to function with a particular type and size of tubing so as to achieve good signal transmission and reception. It is appreciated that if a tubing of a different diameter or type is used, the signal pathway is often interrupted, or the signal does not pass properly through the tube. Thus, a universal air bubble detector should ensure proper signal transmission and reception (signal coupling) with a variety of tubing diameters and types. Poor signal coupling typically results in errors and unreliable operation of the device.
There is thus a need for a universal air bubble detector which may be used in many different situations by allowing for mounting in a variety of locations such as at a piece of equipment or very near to a patient. Such a universal air bubble detector should accommodate a variety of different tubing diameters while maintaining good signal transmission through the tubing. Such an air bubble detector should have stand alone control circuitry and alarms or be able to connect to and communicate with associated equipment such as a delivery pump, or both.